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Trace Elements in Abiotic and Biotic Environments
Following exposures, Ga is transported in blood, bound to transferring, and may
have an impact on upregulating the transferrin receptor. The gallium–transferrin
complex appears to be the primary mechanism by which the Ga ions are presented
to the target cellular system (IARC 2006).
Pure Ga is not a harmful substance for humans, to touch. However, it is known
to leave a stain on hands. Even the Ga radioactive compound, Ga citrate, can be
injected into the body and used for Ga scanning, without harmful effects. Although
it is not harmful in small amounts, Ga should not be consumed in large doses. Some
Ga compounds can be very dangerous. For example, acute exposure to Ga 3+ chloride
can cause throat irritation, difficulty in breathing, chest pain, whereas its fumes can
cause even very serious conditions, such as pulmonary edema and partial paralysis.
Gallium nitrate (brand name Ganite) has been used as an intravenous pharmaceutical to treat hypercalcemia, associated with tumor metastasis to bones. Gallium is
thought to interfere with osteoclast function. Gallium-67 salts, such as Ga citrate and
Ga nitrate, are used as radiopharmaceutical agents in a nuclear medicine imaging
procedure, commonly referred to as a gallium scan. The form or salt of Ga are not
important, as it is the free dissolved ion Ga 3+ , which is the active radiotracer.
Gallium arsenide (GaAs), is extensively used in the microelectronics industry,
because of its photovoltaic properties. The toxicity of GaAs, a compound extensively
used in defense as a superior semiconductor material, in ground- and space-based
radar and in electronic warfare, is not well known. Results from recent reports on
experimental animals indicate that GaAs produces profound effects on lung, liver,
immune, and hematopoietic systems. GaAs is found to be soluble in aqueous solution
and forms unidentified Ga and As species, upon dissolution. Different As species,
which are formed following the exposure to Ga, may lead to various toxic effects
(Flora and Das Gupta 1994).
Exposure to GaAs can only be monitored by determining As concentrations.
Several reports describe the assessment of exposure to As during GaAs production
and use. Although the solubility of GaAs in pure water is very low, its dissolution in
body fluids is greatly enhanced by endogenous chelating molecules. When incubated
in artificial body fluid (Gamble’s solution), GaAs progressively releases both Ga and
As. Gallium arsenide is carcinogenic to humans (Group 1) (IARC 2006).
Over the past two to three decades, Ga compounds have gained importance in the
fields of medicine. Although Ga has no known physiologic function in the human
body, certain characteristics enable it to interact with cellular processes and biologically important proteins, especially those of the Fe metabolism. This has led to
the development of a certain Ga compound, as diagnostic and therapeutic agents in
medicine, especially in the areas of metabolic bone disease, cancer, and infectious
disease (Chitambar 2010).
Gallium has shown efficacy in the treatment of several diverse disorders: (1) accelerated bone resorption, with or without elevated plasma Ca; (2) autoimmune disease
and allograft rejection; (3) certain cancers; and (4) infectious disease. Gallium is
effective in suppressing bone resorption and, when present, concomitant elevated
plasma Ca. This antiresorptive activity has led to its clinical use in treating hypercalcemia of malignancy and Paget’s disease of bone. Gallium has also shown clinical
Trace Elements in Abiotic and Biotic Environments
Following exposures, Ga is transported in blood, bound to transferring, and may
have an impact on upregulating the transferrin receptor. The gallium–transferrin
complex appears to be the primary mechanism by which the Ga ions are presented
to the target cellular system (IARC 2006).
Pure Ga is not a harmful substance for humans, to touch. However, it is known
to leave a stain on hands. Even the Ga radioactive compound, Ga citrate, can be
injected into the body and used for Ga scanning, without harmful effects. Although
it is not harmful in small amounts, Ga should not be consumed in large doses. Some
Ga compounds can be very dangerous. For example, acute exposure to Ga 3+ chloride
can cause throat irritation, difficulty in breathing, chest pain, whereas its fumes can
cause even very serious conditions, such as pulmonary edema and partial paralysis.
Gallium nitrate (brand name Ganite) has been used as an intravenous pharmaceutical to treat hypercalcemia, associated with tumor metastasis to bones. Gallium is
thought to interfere with osteoclast function. Gallium-67 salts, such as Ga citrate and
Ga nitrate, are used as radiopharmaceutical agents in a nuclear medicine imaging
procedure, commonly referred to as a gallium scan. The form or salt of Ga are not
important, as it is the free dissolved ion Ga 3+ , which is the active radiotracer.
Gallium arsenide (GaAs), is extensively used in the microelectronics industry,
because of its photovoltaic properties. The toxicity of GaAs, a compound extensively
used in defense as a superior semiconductor material, in ground- and space-based
radar and in electronic warfare, is not well known. Results from recent reports on
experimental animals indicate that GaAs produces profound effects on lung, liver,
immune, and hematopoietic systems. GaAs is found to be soluble in aqueous solution
and forms unidentified Ga and As species, upon dissolution. Different As species,
which are formed following the exposure to Ga, may lead to various toxic effects
(Flora and Das Gupta 1994).
Exposure to GaAs can only be monitored by determining As concentrations.
Several reports describe the assessment of exposure to As during GaAs production
and use. Although the solubility of GaAs in pure water is very low, its dissolution in
body fluids is greatly enhanced by endogenous chelating molecules. When incubated
in artificial body fluid (Gamble’s solution), GaAs progressively releases both Ga and
As. Gallium arsenide is carcinogenic to humans (Group 1) (IARC 2006).
Over the past two to three decades, Ga compounds have gained importance in the
fields of medicine. Although Ga has no known physiologic function in the human
body, certain characteristics enable it to interact with cellular processes and biologically important proteins, especially those of the Fe metabolism. This has led to
the development of a certain Ga compound, as diagnostic and therapeutic agents in
medicine, especially in the areas of metabolic bone disease, cancer, and infectious
disease (Chitambar 2010).
Gallium has shown efficacy in the treatment of several diverse disorders: (1) accelerated bone resorption, with or without elevated plasma Ca; (2) autoimmune disease
and allograft rejection; (3) certain cancers; and (4) infectious disease. Gallium is
effective in suppressing bone resorption and, when present, concomitant elevated
plasma Ca. This antiresorptive activity has led to its clinical use in treating hypercalcemia of malignancy and Paget’s disease of bone. Gallium has also shown clinical